When observing a comet please try to forget how bright you think the comet
should be, what it was when you last viewed it, what other observers think
it is or what the ephemeris says it should be.

The equations for the light curves of comets that are currently visible
use only the raw observations and should give a reasonable prediction for
the current brightness. If the comet has not yet been observed or has
gone from view a correction for aperture is included, so that telescopic
observers should expect the comet to be fainter than given by the equation.
The correction is about 0.033 per centimetre. Values for the r parameter
given in square brackets [ ] are assumed. The form of the light curve is
either the standard m = H0 + 5 log d + K0 log r or the linear brightening
m = H0 + 5 log d + L0 abs(t - T + D0) where T is the date of perihelion,
t the present and D0 an offset, if L0 is +ve the comet brightens towards
perihelion and if D0 is +ve the comet is brightest prior to perihelion.

Observations of new comets are given in ICQ format. More
recent ones may be available in TA format from the main page.

Full details of recently discovered objects will not appear until they are
available on the CBAT web pages, which is usually a fortnight after the
publication of the IAUC.

It seems rather likely that the two Kracht group comets C/2009 L8 and
C/2009 L13 were previously observed as one
(or maybe two) of the Kracht members of May 2004 (C/2004 J4, 2004 J12,
2004 J13, 2004 J15, 2004 J16, 2004 J17, 2004 J18 and 2004 J20; see MPEC
2004-M71, 2004-N04, 2004-N05 and 2007-K65). Identity with comets C/2004 A3 or
C/2004 B3 (suggested by K. Battams) or with C/2004 L10 (which itself was
perhaps a return of comet C/1999 M3) seems a less likely prospect. Given the
poor quality of the observations, the computation of a definite linkage is
further complicated by the fact that there would have been an approach to within some
1.2 AU of Jupiter in 2008.

Brian Marsden published a linked orbit on MPEC 2009-H56 [2009 April 26] and notes:

The above computation, using nongravitational parameters A1 = +0.0002,
A2 = -0.0002, is based on work by R. Kracht. Despite the poor quality of the
SOHO observations, a purely gravitational computation from the four
apparitions appears to leave significantly systematic residuals.

This suggests that the object really is a comet, and should therefore be numbered as such.
2009 A1 (STEREO)(IAUC )
This was a non-group comet discovered in HI1A images by Alan Watson on
2009 January 13. Dimitry Chestnov and Rainer Kracht computed preliminary orbits,
and Karl Battams was then able to get additional measurements from HI1B. There was
a chance that ground based southern hemisphere observers might be able to image it
when it emerged from solar conjuction in late January, but it was not seen.
A/2009 AU1 [Tozzi]
This unusual asteroid was discovered by Italian amateur astronomer Fabrizio Tozzi,
working remotely with the Sierra Stars 0.6m reflector on January 3.29. It was initially
confirmed by himself using other remote observatories. Follow-up observations show a
stellar appearance to the 18th magnitude object.
It has a period of 9.7 years and perihelion was at
2.3 AU in late July 2008. [MPEC 2009-A48, 2009 January 8, 9-day orbit].
There have been no recent close encounters with Jupiter or the Earth. The Tisserand
criterion with respect to Jupiter is 2.77
This type of orbit is typical of Jupiter family comets.
A/2009 AU16 [Siding Spring]
This unusual object was discovered during the Siding Spring Survey with the 0.5m Uppsala Schmidt on January 6.55.
It has a period of 260 years and it was discovered near the time of perihelion, which was at 1.9 AU.
[MPEC 2009-B21, 2009 January 20, 13-day orbit]. With a Tisserand parameter of 1.84 and an absolute
magnitude of 16, it is clearly a candidate for an extinct comet nucleus.
2009 B1 (P/Boattini)
Andrea Boattini discovered an 18th magnitude comet during the Catalina Sky Survey with the 0.68m Schmidt on
January 21.07. Several observers confirmed the cometary nature.
Further observations allowed the comet to be found on CSS images from November 2008.
The comet has a period of around 17 years and perihelion is at 2.4 AU in early February.
2009 B2 (LINEAR)
An apparently asteroidal 19th magnitude object discovered by LINEAR on January 29.47 was found to
show cometary characteristics by other astrometrists. The
comet reached perihelion at 2.3 AU in early March. It is in a periodic orbit of around 270 years.

Brian Marsden notes on MPEC 2009-G11 [2009 April 4] that

The "original" and "future" barycentric values of 1/a are +0.024104
and +0.024593 (+/- 0.000001) AU^-1, respectively.

The large "original" value shows that this comet has made a previous
visit to the inner solar system.
2009 B3 (213P/Van Ness)
Comet 2005 R2 (P/Van Ness) was recovered by Gary Hug with his 0.56-m reflector at Sandlot Observatory
on January 31.36.
The indicated correction to the prediction on MPC 62889 is Delta(T) = -0.1 day.
2009 B4 (214P/LINEAR)
Comet 2002 CW134 (P/LINEAR) was also recovered by Gary Hug with his 0.56-m reflector at Sandlot Observatory,
on January 31.49.
The indicated correction to the prediction on MPC 56802 is Delta(T) = -0.32 day.
2009 B5 (215P/NEAT)
Comet 2002 O8 (P/NEAT) was also recovered by Gary Hug with his 0.56-m reflector at Sandlot Observatory,
on January 22.49. The comet was 20th magnitude.
The indicated correction to the prediction on MPC 59599 is Delta(T) = -0.34 day.

In September, Maik Meyer detected the comet on two SERC-J plates taken in September and October
1994. The two trails appeared slightly diffuse.

A/2009 BL80 [LINEAR]
This unusual object was discovered by LINEAR with the 1.0-m reflector on January 31.
It has a period of 15 years, perihelion at 2.2 AU and a Tisserand criterion value of 2.51. [MPEC 2009-C77, 2009 February 11, 103-day orbit].
It has made no recent close approaches to Jupiter.
A/2009 CS [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m Schmidt on February 2.41.
18th magnitude at discovery it has a period of around 5.3 years and perihelion was at 0.79 AU in early December 2008 [MPEC 2009-C24, 2009 February 3, 1-day orbit].
The object can pass within 0.3 AU of Jupiter and 0.04 AU of the earth. This type of orbit is typical of Jupiter family comets.
A/2009 CR2 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m Schmidt on February 3.30.
19th magnitude at discovery it has a period of 5.4 years and perihelion was at 1.10 AU in mid June [MPEC 2010 H30, 2010 April 20].
The object can pass within 0.1 AU of Jupiter and 0.10 AU of the earth. This type of orbit is typical of Jupiter family comets and has a Tisserand
criterion value of 2.87.
2009 D1 (216P/LINEAR)
Comet 2001 CV8 (P/LINEAR) was recovered by Jim Scotti with the Spacewatch 1.8-m reflector
on February 19.53.
The indicated correction to the prediction on MPC 54170 is Delta(T) = -0.37 day.
A/2009 DD47 [LINEAR]
This unusual object was discovered by LINEAR with the 1.0-m reflector on February 27.34.
It has a retrograde orbit with a period of around 65 years, perihelion at 2.1 AU, aphelion at over 30 AU
and a Tisserand criterion value of 2.08. Perihelion was in 2008 October. [MPEC 2009-E12, 2009 March 2, 3-day orbit].
It has made no recent close approaches to Jupiter or Saturn.

Numerous attempts were made to detect cometary appearance in March, but none succeeded [IAUC 9035, 2009 April 7]

The comet was at perihelion in early April at 0.6 AU. At discovery it was visible in the early evening sky,
but was too close to the Sun for observation by the end of March. After perihelion UK observers may recover it in June,
however by then it will have faded to around 13th magnitude. An early orbit by Hirohisa Sato suggested an ellipse with a period of
around 200 years and the latest orbit gives 250 years.

Brian Marsden notes on MPEC 2009-L10 [2009 June 3] that

The "original" and "future" barycentric values of 1/a are +0.025613
and +0.025159 (+/- 0.000007) AU^-1, respectively.

The large "original" value shows that this comet has made a previous
visit to the inner solar system.
2009 F1 (Larson)
Steve Larson discovered a 19th magnitude comet on survey images taken with the Mt Lemmon 1.5-m reflector on March 16.43. It was
confirmed by several CCD imagers, including Peter Birtwhistle. The preliminary
orbit is retrograde with perihelion at 1.8 AU in late June. It moves in a long period elipse with a period of around 1000 years.
The comet will only brighten a little.

Brian Marsden notes on MPEC 2009-K68 [2009 May 29] that further
[astrometric] observations of this comet are desirable.

2009 F2 (McNaught)
Rob McNaught discovered an 18th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
March 19.58. It is a distant comet with perihelion at 5.9 AU in November. It has a period of around 7000 years.

Brian Marsden notes on MPEC 2009-L11 [2009 June 3] that

The "original" and "future" barycentric values of 1/a are +0.002783
and +0.003054 (+/- 0.000032) AU^-1, respectively.

The large "original" value shows that this comet has made a previous
visit to the inner solar system.
2009 F3 (217P/LINEAR)
Comet 2001 MD7 (P/LINEAR) was recovered by Ernesto Guido, Giovanni Sostero and Paul Cammileri on March 17.50 using
remote telescopes in the USA (the RAS Observatory 0.25-m reflector near Mayhill, NM) and in Australia (the 0.35-m reflector at
Grove Creek Observatory, Trunkey, N.S.W.). The comet was 18th magnitude. The indicated correction to the predictions on
MPC 56804 is Delta(T) = +0.01 day. It is a reasonably favourable return and the comet could reach 12th
magnitude near the time of perihelion, coming into view for UK observers in August.
2009 F4 (McNaught)
Rob McNaught discovered another 18th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
March 19.68. It is also a distant comet, with perihelion at 5.5 AU in 2011 December.

The "original" and "future" barycentric values of 1/a are -0.000078
and -0.000016 (+/- 0.000101) AU^-1, respectively.

The small "original" value shows that this comet is on its first
visit to the inner solar system.
2009 F5 (McNaught)
Rob McNaught discovered a 16th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
March 20.66. It was at perihelion at 2.2 AU in 2008 November. It is in a long period orbit of around 700 years.

Brian Marsden notes on MPEC 2009-L13 [2009 June 3] that

The "original" and "future" barycentric values of 1/a are +0.012472
and +0.012849 (+/- 0.000041) AU^-1, respectively.

The large "original" value shows that this comet has made a previous
visit to the inner solar system.
2009 F6 (Yi-SWAN)
On April 4 Rob Matson reported a possible 9th magnitude comet seen in SOHO-SWAN images between March 29 and April 4. This was soon confirmed as a comet by
ground based astrometrists. Following the initial IAUC, the CBAT received a message that a comet had been discovered by Dae-am Yi of Korea on DSLR images
that he had taken on March 26. Orbital calculation showed that the two objects were identical. The comet was at perihelion in early May at 1.3 AU.
It became a diffuse object and no visual observations have been reported since late May. CCD observations in late August and early September give
the total magnitude as around 16.5, much fainter than expected from the visual light curve.

With such a bright object it is surprising that patrol images did not pick it up earlier. One reason is its location in the Milky Way, which is often avoided
by the professional search programmes and its orbit is almost exactly along the plane of our galaxy. At least one amateur imager did locate the comet:

Stanislav Korotkiy (Ka-Dar obs., Moscow, Russia) reports that during the patrol
photographic survey of the Milky Way he photographed a comet C/2009 F6 on 2009
March 25, 01:26 UT (one day before discovery). He used Canon EOS 20D digital
camera + 50-mm f/4 lens. Limiting magnitude was about 13m. During first
processing of images no new objects was detected. After a publication of MPEC
2009-G21 that announced an orbit for a new comet C/2009 F6, the images was
processed again and a comet was found near the calculated position.

Brian Marsden notes on MPEC 2009-S14 [2009 September 17] that

The "original" and "future" barycentric values of 1/a are +0.001440
and +0.002210 (+/- 0.000016) AU^-1, respectively.

The large "original" value suggests that this comet has made a previous
visit to the inner solar system.
2009 F7 (218P/LINEAR)
On March 31 the LINEAR team reported a possible recovery of comet 2003 H4 (P/LINEAR) and this was confirmed by Giovanni Sostero, E Propsperi,
Ernesto Guido and Paul Cammileri on April 15 using a remote telescope in Australia (the 0.35-m reflector at
Grove Creek Observatory, Trunkey, N.S.W.). The comet was 20th magnitude. The indicated correction to the predictions on
MPC 56804 is Delta(T) = -0.13 day.
A/2009 FW23 [Siding Spring]
This unusual object was discovered during the Siding Spring Survey with the 0.5m Uppsala Schmidt on March 19.52.
It has a period of about 35 years, with a near perpendicular inclination.
It was discovered about a month after perihelion, which was at 1.7 AU. It has an absolute
magnitude of 15.
[MPEC 2009-F72, 2009 March 24, 5-day orbit]. With a Tisserand parameter of 2.01, on the boundary between
a Jupiter family comet and an intermediate period comet, it may be a candidate for an extinct comet nucleus.
It has however made no recent approaches to either Jupiter or Saturn.
2009 G1 (STEREO)(IAUC )
Jiangao Ruan discovered a non-group comet in HI1B images from April 5 on
April 8. It was at perihelion at 1.1 AU in mid April.
Its elongation from the Sun was increasing, and ground based observers were able to imaged it allowing a good
orbit to be computed. It
will be predominantly a Southern Hemisphere object. It was around 9th magnitude and near its brightest at discovery
and is now slowly fading.

Hirohisa Sato notes that the best fit orbit is slightly elliptical and the latest orbit has a period of nearly 10,000 years.

Brian Marsden notes on MPEC 2009-N14 [2009 July 6] that

The "original" and "future" barycentric values of 1/a are +0.002337
and +0.002432 (+/- 0.000057) AU^-1, respectively.

The moderate "original" value shows that this comet has probably made a previous
visit to the inner solar system.
2009 G8 (SOHO)(IAUC )
This was a non-group comet discovered in C2 images by Bo Zhou on
2009 April 13.
2009 H1 (219P/LINEAR)
Ernesto Guido, Giovanni Sostero, Paul Cammileri and E Propsperi recovered comet 2002 LZ11 (P/LINEAR) on April 17.45
using a remote telescope in the USA (a 0.25-m reflector near Mayhill, New Mexico). The comet was 19th magnitude. The indicated correction to the predictions on
MPC 59599 is Delta(T) = -0.4 day.
2009 H2 (220P/McNaught)
Automatic analysis of data from April 28 provided to the Minor Planet Centre by Spacewatch identified comet P/2004 K2 (McNaught). The comet
was also independently recovered by Gustavo Muler, J. M. Ruiz and Ramon Naves with the 0.30-m Schmidt-Cassegrain at the Observatorio Nazaret (Lanzarate,
Spain) on May 1 and 3. The indicated correction to the prediction on MPC 56805 is Delta(T) =
-0.08 day.
A/2009 HC82 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m Schmidt on April 29.37.
20th magnitude at discovery it has a retrograde orbit with a period of around 3.4 years and perihelion was at 0.40 AU on 2008 November 7 [MPEC 2009-J04, 2009 May 1, 2-day orbit].
The object can pass within 0.0235 AU of the earth, but does not pass particularly close to Jupiter. It has a Tisserand criterion value of 3.06.
2009 K1 (P/Gibbs)
Alex Gibbs discovered a 19th magnitude comet on survey images taken with the Mt Lemmon 1.5-m reflector on May 16.15.
The preliminary orbit gave perihelion at 1.5 AU in mid June, but it had a small inclination and was likely to be periodic.
The comet will only brighten a little. Further observations confirmed the short period orbit, and both the CBAT and Hirohiso Sato
computed orbits. Perihelion was at 1.3 AU in late June and the period around 7.1 years.
2009 K2 (Catalina)
A 19th magnitude object discovered by the Catalina Sky Survey with the 0.68m Schmidt on May 18.33 was found to show cometary features by
other observers, including Peter Birtwhistle.
The comet reaches perihelion at 3.2 AU in 2010 February. It may reach 16th magnitude.

Brian Marsden notes on MPEC 2009-P11 [2009 August 3] that

The "original" and "future" barycentric values of 1/a are +0.001106
and +0.001305 (+/- 0.000020) AU^-1, respectively.

The moderate "original" value shows that this comet has probably made a previous
visit to the inner solar system.
2009 K3 (Beshore)
Ed Beshore discovered a 20th magnitude comet on survey images taken with the Mt Lemmon 1.5-m reflector on May 26.16.
The preliminary orbit gives perihelion at 3.9 AU in 2011 January.

Brian Marsden notes on MPEC 2009-N15 [2009 July 6] that further
[astrometric] observations of this comet are extremely desirable.

2009 K4 (Gibbs)
Alex Gibbs discovered a 17th magnitude comet on Catalina Sky Survey images taken with the 0.68m Schmidt on May 27.15.
The comet is at perihelion at 1.5 AU in mid June. The comet will remain at a similar brightness over the next
month.

Computations by Hirohisa Sato suggest that a long period orbit is also possible and this was confirmed by later orbits.

Brian Marsden notes on MPEC 2009-P12 [2009 August 3] that

The "original" and "future" barycentric values of 1/a are +0.023510
and +0.023929 (+/- 0.000000) AU^-1, respectively.

The large "original" value shows that this comet has made a previous
visit to the inner solar system.
2009 K5 (McNaught)
Rob McNaught discovered an 18th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
May 27.61. The comet reached perihelion at 1.4 AU in late April 2010 and was around 8th magnitude. By mid May it was fading.

The "original" and "future" barycentric values of 1/a are +0.000020
and +0.000485 (+/- 0.000039) AU^-1, respectively.

The small "original" value shows that this comet is on its first
visit to the inner solar system.
A/2009 KC3 [Siding Spring]
This object was discovered during the Siding Spring Survey with the 0.5m Uppsala Schmidt on May 23.65 at around 19th magnitude.
It has a period of about 5.7 years, with perihelion at 1.0 AU in August. It will brighten to around 16th magnitude in late August
when it passes 0.05 AU from the Earth.
[MPEC 2009-K39, 2009 May 24, 20-day orbit]. It has a Tisserand parameter of 2.75 and may be a candidate for an extinct comet nucleus.
It can approach Jupiter to within 0.2 AU, most recently around 1956, and has an Earth MOID of 0.0098 AU.
2009 L1 (221P/LINEAR)
Leonid Elenin, Lyubertsy, Moscow region, Russia, has recovered comet P/2002 JN16 as part of the
ROCOT project.
On June 1.40, he detected a diffuse object (~20.2m) with a small tail on 16 images obtained on 0.36-m f/3.8 Maksutov-Newtonian + ST-10XME
(Tzec Maun observatory, Mayhill, NM, USA).
The next day he requested confirmation of the recovery, and
Michael Schwartz at Tenagra observatory imaged the comet on June 3 with 0.81-m f/7 Ritchey-Chretien + SITe.
These images clearly show a tail at PA 248 degrees and length about 35".
The correction to the predictions on MPC 56802 is Delta(T) = -0.2 day.
2009 L2 (P/Yang-Gao)
Rui Yang, Hangzhou, Zhejiang, China and Xing Gao, Urumqi, Xinjiang, China discovered a new comet on several survey images (limiting mag about 15)
taken by Gao in the course of the Xingming Comet Survey using a Canon 350D camera (+ 10.7-cm
f/2.8 camera lens) at Mt. Nanshan on June 15.81. The object, of 14th magnitude, but perhaps brighter visually,
was identified as cometary by Yang. It was confirmed by several amateur CCD observers. [IAUC 9052, 2009 June 16]. The comet was around a month past perihelion at 1.3 AU
at a very favourable opposition and has a period of 6.3 years. This is the second discovery by the Xingming Survey, the first being 2008 C1 (Chen-Gao)
2009 L18 (P/Skiff)
G. Sostero, E. Guido, P. Camilleri and E. Prosperi recovered P/Skiff (2002 S1) on June 15.61 from the co-addition of forty
unfiltered 60-s CCD exposures obtained remotely on June 15.6 UT with the 0.35-m f/7 reflector at the Skylive-Grove Creek
Observatory (near Trunkey, NSW, Australia). The recovery was confirmed by them on August 18.58. The comet was 20th magnitude
and of stellar appearance. The indicated correction to the predictions on MPC 59600 is Delta(T) = -0.16 day.
2009 M8 (SOHO)(IAUC )
This was a non-group comet discovered in C2 images by Rainer Kracht on
2009 June 30.
2009 MB9 (222P/LINEAR)
Rob McNaught discovered an 18th magnitude asteroid on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
June 29.47. On a subsequent observing run on August 2.38 he noted that the object appeared cometary. Hirohiso Sato pointed out that the
object appears to be comet P/LINEAR (2004 X1); the indicated correction to the prediction on MPC
56804 being Delta_T = -2.2 days.
The comet has a period of 4.83 years and reaches perihelion at 0.78 AU on September 1.1.
2009 N1 (SOHO)(IAUC )
This was a non-group comet discovered in C2 images by Bo Zhou on
2009 July 3.
2009 N3 (SOHO)(IAUC )
This was a non-group comet discovered in C2 images by Bo Zhou on
2009 July 5.
A/2009 NE [LINEAR]
This somewhat unusual object was discovered by LINEAR with the 1.0-m reflector on July 2.28.
It has a period of 4.4 years, with perihelion at 0.36 AU,
and a Tisserand criterion value of 2.67. Perihelion is in 2009 October. [MPEC 2009-N13, 2009 July 6].
It has made no recent close approaches to Jupiter and can pass 0.44 AU from Earth.
2009 O2 (Catalina)
A 19th magnitude object discovered by the Catalina Sky Survey with the 0.68m Schmidt on July 27.30 was found to show cometary features by
other observers. Peter Birtwhistle also contributed initial astrometric observations.
The comet will reach perihelion at 0.7 AU in 2010 March and has a very long period orbit of about 4000 years.
It may reach 9th magnitude, or brighter if activity switches on, and will be well
placed for observation from the UK when at its brightest.

Although it had brightened to around 11th magnitude by early March, observations on March 12 showed
a much more diffuse coma than they had on March 5. It has a relatively faint absolute magnitude of 11, so it
is possible that the comet is disintegrating, on the other hand the orbit suggests that it has survived previous
perihelion passages. The comet has remained at around 11th magnitude into April, but remains diffuse.

Brian Marsden notes on MPEC 2010-G63 [2010 April 9] that

The "original" and "future" barycentric values of 1/a are +0.000348
and +0.004119 (+/- 0.000003) AU^-1, respectively.

The moderate "original" value suggests that this comet has made a previous
visit to the inner solar system.
2009 O3 (P/Hill)
An 18th magnitude comet was discovered by Rik Hill during the Catalina Sky Survey with the 0.68m Schmidt on July 29.43.
Peter Birtwhistle contributed initial astrometric observations.
The comet has a period of 22 years and was at perihelion at 2.4 AU in 2009 May.
2009 O4 (Hill)
Rik Hill discovered a 16th magnitude comet the following night on July 30.37, again during the Catalina Sky Survey with the 0.68m Schmidt.
The comet will reach perihelion at 2.6 AU in early January 2010. It was at opposition in September
and is unlikely to become brighter than 15th magnitude. Calculations by Hirohisa Sato suggested that a hyperbolic orbit was also possible,
with similar T and q. This was confirmed by MPEC 2009-S146.

Brian Marsden notes on MPEC 2009-S146 [2009 September 30] that

The "original" and "future" barycentric values of 1/a are +0.000080
and -0.000037 (+/- 0.000030) AU^-1, respectively.

The small "original" value shows that this comet is on its first
visit to the inner solar system.
2009 P1 (Garradd)
Gordon Garradd discovered a 17th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
August 13.77. The comet reached perihelion at 1.6 AU in December 2011.

Visual observations were reported in 2010 August, with the comet already 13th magnitude. It had reached 8.5 by 2011 July,
although the rate of brightening was relatively slow. It reached a first peak of around 7.5 towards the
end of August, though some observers continued to record it brightening for
another month or two. This perhaps
implies that not all observations are independent, and there is a certain amount
of “following the trend”. It was widely observed during the first half of
2012, reaching 6th magnitude at its brightest. It is now poorly placed for
observation and fading.

The "original" and "future" barycentric values of 1/a are +0.000446
and +0.000192 (+/- 0.000389) AU^-1, respectively.

The moderate "original" value shows that this comet may have made a previous
visit to the inner solar system.
2009 P2 (Boattini)
Andrea Boattini discovered a 19th magnitude comet during the Catalina Sky Survey with the 0.68m Schmidt on
August 15.44. Several amateur observers confirmed the cometary nature. It was later linked to the
same object as asteroids 2008 TQ137 and 2008 VP28. The comet will reach
perihelion at 6.5 AU in 2010 February.

Brian Marsden notes on MPEC 2009-R29 [2009 September 9] that

The "original" and "future" barycentric values of 1/a are +0.000021
and +0.000048 (+/- 0.000006) AU^-1, respectively.

The small "original" value shows that this comet is on its first
visit to the inner solar system.
2009 Q1 (P/Hill)
Rik Hill discovered an 18th magnitude comet on August 27.40, during the Catalina Sky Survey with the 0.68m Schmidt.
The comet was at perihelion at 2.8 AU in July and has a period of 13 years.
This is the 100th comet found by the Catalina and Mt Lemmon team.

Rob Matson found images of the comet on three Heleakala-NEAT images from 1996, which in turn allowed him to find it in
two more nights from 1998. It was very bright in the 1996 images
showing obvious coma, but barely detectable in 1998.

2009 Q2 (P/LINEAR-NEAT)
Jim Scotti recovered 2003 XD10 (P/LINEAR-NEAT) with the Spacewatch 1.8-m f/2.7 reflector at Kitt Peak on August 27.39.
The comet was 21st magnitude and of stellar appearance. The indicated correction to the prediction on MPC 59598 is
Delta(T) = -0.10 day.
2009 Q3 (P/LINEAR)
Jim Scotti recovered 2002 T1 (P/LINEAR) with the Spacewatch 1.8-m f/2.7 reflector at Kitt Peak on August 28.49.
The comet was 21st magnitude and of near-stellar ("soft") appearance. The indicated correction to the prediction on MPC 56804 is
Delta(T) = +0.04 day.
2009 Q4 (P/Boattini)
Andrea Boattini discovered a 19th magnitude comet during the Catalina Sky Survey with the 0.68m Schmidt on
August 26.47. Several amateur observers confirmed the cometary nature. The comet will reach perihelion at 1.3 AU in mid November and
has a period of 5.6 years.
2009 Q5 (P/McNaught)
Rob McNaught discovered an 17th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
August 31.63. The comet was near perihelion at 2.9 AU.
This is Rob McNaught's 50th comet discovery. The comet has a period around 20 years.
2009 QG31 (P/La Sagra)
An apparently asteroidal object of 18th magnitude discovered on CCD images taken remotely in the course of the "La Sagra Sky Survey" (LSSS),
with a 0.45-m f/2.8 reflector located at Sagra mountain in southeastern Spain, was found to show cometary appearance by
CCD astrometrists elsewhere. The observation on August 19.05 was assigned "discovery" status after the Minor Planet Center
linked "one-night" LSSS observations made on August 19 with others made on August 25 (though earlier LSSS observations were
made on August 16), and later LSSS and Catalina observations linked by the MPC allowed the issuance a comet-like orbit on September 8,
in the daily aggregate of new orbits (MPEC 2009-R26). [IAUC 9078, 2009 September 29]
The comet was at perihelion in mid October at 2.1 AU and has a period of 6.8 years.

Reiner Stoss notes the following discovery story on behalf of the LSSS team

Exactly one year ago fellow asteroid hunter Patrick Wiggins
posted on MPML his joy about his latest asteroid discovery.
You can find the thread in the MPML archive (subject:
"It's still possible"). His conclusion was that it is still
possible for amateurs to find "bright" asteroids, despite the
huge sky coverage by the NASA NEO surveys.

In an attempt to underline this and to motivate other fellow
observers I had then posted some experiences made in the first few
months of our own sky survey. After just three months of permanently
scanning the skies we had received around one thousand designations
from MPC and the sky seemed to be full of unidentified asteroids,
some of them as bright as magnitude 17.

Now, exactly one year later, the situation has not changed significantly.
At J75 we keep scanning with the 45-cm and we find lots of new stuff ranging
from magnitude 18 to 20. Sometimes as many as a few hundred possibly
new objects per night. It shows that finding new asteroids is not
a matter of luck, just a function of search area and limiting
magnitude... and more or less the same applies to comets I guess.

We have missed a few of them in the past, either because they were
just outside the search area. Or because of some other "constraints"
(see below). Now we finally scored one and this one would have gone
unnoticed too if MPC wouldn't have linked it to other survey
observations so that it showed a cometary orbit and drew special
attention therefore. Finding one is way more difficult than finding
an asteroid, even a NEO. But I guess it comes too more or less guaranteed
after a lot of searching, like with asteroids.

Definitely the times are much harder now compared to the age when
Dennis di Cicco wrote his famous "Hunting Asteroids From Your Backyard"
article 15 years ago. At that time nearly every mover on the sky was
a new one, even at magnitude 16. The big surveys are now in operation
since more than 10 years and the number of objects that have been
discovered and have received orbits has virtually exploded, from
around 29,000 in early January 1996 to more than 460,000 objects now
(out of these were 6,800 numbered then vs. 220,000 numbered objects now).

I am not into visual comet hunting, but I think to remember that
these folks invested on average hundreds of hours per discovery.
Clearly their work was very difficult, learning all those faint galaxies
to distinguish them from possible comets without using star maps and a
light to not destroy the adaption of the eyes. Today's work is rather
different. Being outside with the telescope under the sky was replaced by
endless sessions on the computer screen watching CCD images scroll
by. Judge yourself what is easier and more pleasurable :o)

I am therefore not able to tell how many hours it took us to score the
first one, but here are a few numbers that might help evaluate how much
"asteroid work" was done (=sky was scanned) until the first new comet
showed up. They are from more or less one year of LSSS operations.

Earlier this month I did extract some numbers for J75 LSSS from the MPC
observations database and I noticed that we had meanwhile published more
than 500,000 observations for a total of 75,000 individual objects.
Thirty percent of all numbered asteroids to date were observed by J75.
And the number of designations received from the MPC is now at 3300.

And still, compared to the numbers delivered by Catalina, LINEAR and
Spacewatch ours are rather humble. We know that we can't compete with
them and it isn't our goal at all. LSSS is working different than
the big surveys. It is an amateur survey done entirely remotely.
Only one operator is permanently at the observatory, while all others
are up to several thousand kilometers away. As all of us have day jobs,
it is only possible to run this survey by using every free minute, being
connected remotely no matter where we currently are.

My LSSS colleague Jaime Nomen is sometimes working via laptop and 3G card
while he is travelling in a high-speed train (AVE) between Barcelona
and Madrid. If you ever happen to use that train and you see someone
getting anxious when the 3G signal is getting weak in one of the tunnels,
you know who it is and what some people do at over 300km/h :o)

Anyway, no matter if you are after asteroids or comets, I think that
the closing sentence of Dennis di Cicco's 1996 article is still true:

"There's a lot of stuff out there waiting to be discovered,
and it doesn't take long to find it!"

... except with some comets :o)

P.S.: As mentioned above, here is one sure way to lose a comet discovery:
Travel to a remote island without taking a 3G card with you!
Some of us were on the island of Lastovo in the Adriatic Sea around New
Year's Eve 2008/2009, unfortunately without Internet. When we returned
on Jan. 2, I checked my email inbox to see the detections made of
possibly new asteroids by our telescopes in the past days. I ran them
through MPChecker just to find this:
-----
The following objects, brighter than V = 23, were found in the 5.0-arcminute
region around the following observation:

-----
We had a comet in the inbox waiting to be reported, right when
we were out of town for a couple of days without Internet.
And then of course comes what must come... Catalina picks
it up, reports it and gets the credit in IAUC 9008 from Jan. 1
Sometimes you lose, sometimes you win :o)

In early 2013 Rob Matson found the comet in NEAT images taken with the Palomar 1.2m Schmidt in 2002 July, and other
images were found in frames from the Apache Point 2.5m telescope.
A/2009 QN5 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m Schmidt on August 18.36.
20th magnitude at discovery it has a period of around 5.9 years and perihelion is at 0.38 AU on 2009 October 21 [MPEC 2009-Q25, 2009 August 19, 1-day orbit].
The object can pass within 0.1216 AU of the earth, and 0.7 AU of Jupiter. It has a Tisserand criterion value of 2.35. Aphelion is at 6.1 AU.
A/2009 QY6 [LINEAR]
This unusual object was discovered by LINEAR with the 1.0-m reflector on August 17.38.
It has a retrograde orbit with period of 18 years, with perihelion at 2.1 AU, aphelion at 11.6 AU
and a Tisserand criterion value of 2.4. Perihelion is in 2009 September. [MPEC 2009-Q32, 2009 August 20].
It does not pass particularly close to any of the major planets - 3.9 AU from Saturn, 2.8 AU from Jupiter and
1.1 AU from Earth.
A/2009 QB36 [LINEAR]
This unusual object was discovered by LINEAR with the 1.0-m reflector on August 29.34.
20th magnitude at discovery it has a period of around 4.5 years and perihelion is at 0.42 AU on 2009 November 20 [MPEC 2009-Q81, 2009 August 30, 1-day orbit].
The object can pass within 0.26 AU of the earth, and 0.1 AU of Jupiter. It has a Tisserand criterion value of 2.68.
2009 R1 (McNaught)
Rob McNaught discovered a 17th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
September 9.62. The comet reaches perihelion at 0.4 AU in early July 2010. It will be an easy binocular
object in 2010 June, perhaps reaching 5th magnitude, though for UK observers it will have dropped into the twilight by the end of the month.

The "original" and "future" barycentric values of 1/a are +0.000064
and -0.000569 (+/- 0.000035) AU^-1, respectively.

The small "original" value shows that this comet is on its first
visit to the inner solar system.
2009 R2 (226P/Pigott-LINEAR-Kowalski)
Rich Kowalski discovered a very diffuse comet during the Catalina Sky Survey with the 0.68m Schmidt on September 10.4, which was
confirmed by several observers including Peter Birtwhistle following posting on the NEOCP as 9R1E5E6. Dimitry Chestnov linked the
object to comet 2003 A1, although the linked orbit had considerably different orbital elements (notably T and q) to those predicted for 2003 A1. Brian
Marsden notes on IAUC 9072: "it is meaningless to indicate a Delta(T) value because the prediction is strongly influenced by a
very close approach to Jupiter (nominally 0.0605 AU on 2006 Sept. 10.4 TT)." He then computed a linked orbit that satisfactorily
included observations of comet Pigott, seen in 1783. The comet was at perihelion in May.

Following publication of the new orbit, Maik Meyer was able to locate images of the comet on Siding Spring images taken on 1995 October 29.

A/2009 RN [OAM]
This unusual asteroid was discovered from the OAM Observatory with a 0.40-m reflector by S. Sanchez, J. Nomen, R. Stoss,
W. K. Y. Yeung, J. Rodriguez, M. Hurtado on September 11.00.
18th magnitude at discovery it has a period of around 5.9 years and perihelion is at 1.0 AU on 2009 November 8 [MPEC 2009-R38, 2009 September 11, 0.4-day orbit].
The object can pass within 0.0096 AU of the earth, and 0.05 AU of Jupiter. It has a Tisserand criterion value of 2.73. It may be a candidate for an extinct
Jupiter family comet. It made a close approach to Jupiter during its most recent orbit.
A/2009 RO [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m Schmidt on September 11.18.
18th magnitude at discovery it has a period of around 6.6 years and perihelion is at 1.37 AU on 2009 September 24 [MPEC 2009-R37, 2009 September 11, 15-day orbit].
The object can pass within 0.4 AU of Jupiter. It has a Tisserand criterion value of 2.78.
2009 S1 (229P/Gibbs)
Alex Gibbs discovered a 19th magnitude comet on September 20.38, during the Catalina Sky Survey with the 0.68m Schmidt.
The comet was at perihelion at 2.4 AU in early August and has a period of 7.8 years.
Richard Miles used the 2.0-m "Faulkes Telescope North" at Haleakala to provide confirming astrometry and images. When an
improved orbit became available, Rob Matson was able to identify images of the comet in NEAT imagery from 2001,
and it was given the identifier 2001 Q10 for this return.
2009 S2 (P/McNaught)
Rob McNaught discovered a 19th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
September 20.68. The preliminary orbit allowed prediscovery observations from August 3 to be located. The comet was at
perihelion at 2.2 AU in June and has a period of around 8.5 years.
2009 S3 (Lemmon)
A 21st magnitude object found during the Mt Lemmon survey with the 1.5-m reflector on September 24.16, was posted on the NEOCP and
found to be diffuse during follow up observations. The comet is a distant one, and
reached perihelion at 6.5 AU at the end of 2011.

Brian Marsden notes on MPEC 2009-W94 [2009 November 24] that further
[astrometric] observations of this comet are desirable.

Following publication of the new orbit, Maik Meyer was able to locate images of the comet on Haleakala-NEAT images taken on 1997 January 15.
Due to the mediocre quality of the images a decision on whether the object showed cometary activity was not possible.
The magnitude was around 19.

2009 SK280 (P/Spacewatch-Hill)
Rik Hill discovered a 20th magnitude comet on October 15.36, during the Mt Lemmon Survey with the 1.5-m reflector. The Minor Planet
Centre then identified it with earlier asteroidal images that had been taken on September 17, 25.29 and 29 by Spacewatch, with the later
two linked under the designation 2009 SK280.
The comet was at perihelion at 4.2 AU in late May and has a period of around 10 years.
A/2009 SK104 [Mt Lemmon]
This unusual object was discovered during the Mt Lemmon Survey with the 1.5-m reflector on September 25.36.
22nd magnitude at discovery it has a period of around 5.7 years and perihelion was at 1.01 AU on 2009 April 13 [MPEC 2009-S111, 2009 September 27, 2-day orbit].
The object can pass within 0.07 AU of the earth, and 0.4 AU of Jupiter. It has a Tisserand criterion value of 2.78. It is a likely
candidate for an extinct comet nucleus.
2009 T1 (McNaught)
Rob McNaught discovered an 18th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
October 9.75. The comet was at perihelion at 6.2 AU in October 2009.

Brian Marsden notes on MPEC 2009-Y10 [2009 December 16] that

The "original" and "future" barycentric values of 1/a are +0.000878
and +0.000942 (+/- 0.000038) AU^-1, respectively.

The moderate "original" value shows that this comet may have made a previous
visit to the inner solar system.
2009 T2 (P/La Sagra)
The "La Sagra Sky Survey" (LSSS) team discovered a second comet with the 0.45-m f/2.8 reflector located at Sagra mountain
in southeastern Spain on October 12.87. This object was 17th magnitude.
The comet is at perihelion in mid January 2010 at 1.8 AU and has a period of 21 years. Richard
Miles (Stourton Caundle, Dorset, England, 0.28-m f/9.4 Schmidt-Cassegrain reflector) writes that
127 stacked 30-s CCD frames taken on October 13.0 show weak cometary appearance with a narrow tail 25"
long in p.a. 230 deg.

Reiner Stoss provides the following discovery information

The big surveys didn't miss it. As can be seen in the discovery
MPEC and IAUC, Catalina did detect it several times before we did,
but it went unnoticed into the huge batch of asteroid ONS data.

MPC then did not link the individual nights because they were not too
close together *and* because you can't link them if you assume
any realistic "asteroid orbit".

The question could be rather why Catalina missed the cometary nature.
I can not answer this question, but I know that it is very easy to miss
it. It almost happened to us too this time and for sure many times
in the past.

First of all surveys (including us) do not make dozens of images per
field to stack them, to see if any object could show a faint coma/tail.
They make just relatively short exposures, to maximize sky coverage
and to minimize trailing losses for fast-movers. P/2009 T2 did not show
a coma or a tail on our survey images from the 45-cm despite the
"fast" optics of f/2.8 . It was the pure brightness of this apparently
new "asteroid" that made me suspicious, so we quickly scheduled
follow-up on our 40-cm tracking telescope. Only those images then
showed the tail (already on 90s exposures) and it became more obvious
after some stacking.

We pick up sometimes hundreds of new V 19.x movers in one night.
We pick up a dozen new V 18.x movers per night and some on
the faint end of V 17 too. But it is highly unusual to find a new
V 17.0 mainbelt asteroid. The NEOR score was low for what became
P/2009 T2 later and its brighness was the only hint that the object
could be unsual.

Contrary to what other surveys do (I think most of them check only
high NEOR objects visually before posting them to the NEOCP)
at LSSS we *do* check each and every new mover visually.
"New" means it can't be IDed with the MPCORB. But depending
on the quality of the night and several other factors, it is often impossible
to tell from survey images if an object is cometary or not, except it
shows a big coma and/or a long tail or you are Rob McNaught :o)

I am therefore sure we missed a few comets at LSSS in the past two
years or so. They were reported together with thousands of other
unidentified asteroidal movers as ONS to the MPC and will get
linked eventually as precovery observations to future comets.

2009 T3 (LINEAR)
An apparently asteroidal object of 19th magnitude discovered by LINEAR with the 1.0-m reflector on October 14.43 was
found to show a cometary appearance by other astrometrists, including Giovanni Sostero and Richard Miles.
The comet will reach perihelion at 2.3 AU in mid January 2010.

Brian Marsden notes on MPEC 2009-Y11 [2009 December 16] that

The "original" and "future" barycentric values of 1/a are +0.000611
and +0.000375 (+/- 0.000076) AU^-1, respectively.

The moderate "original" value shows that this comet may have made a previous
visit to the inner solar system.
2009 U1 (Garradd)
Gordon Garradd discovered a 20th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
October 17.71. The preliminary orbit suggests that the comet reaches perihelion at 3.0 AU in July 2010.

Brian Marsden notes on MPEC 2009-X21 [2009 December 8] that further
[astrometric] observations of this comet are extremely desirable.

2009 U2 (228P/LINEAR)
Jim Scotti recovered P/2001 YX127 with the 1.8-m Spacewatch telescope at Kitt Peak on October 18.45, noting that it was very faintly
diffuse with a short tail.
The indicated correction to the orbit prediction on MPC 62881 is Delta T = -0.36 day.
2009 U3 (Hill)
Rik Hill discovered an 18th magnitude comet on October 21.32 during the Catalina Sky Survey with the 0.68m Schmidt.
The comet will reach perihelion at 1.4 AU in March 2010, when it is predicted to reach around 15th magnitude.

Brian Marsden notes on MPEC 2009-Y12 [2009 December 16] that

The "original" and "future" barycentric values of 1/a are +0.006289
and +0.005921 (+/- 0.000065) AU^-1, respectively.

The large "original" value shows that this comet has made a previous
visit to the inner solar system.
2009 U4 (P/McNaught)
Rob McNaught discovered a 17th magnitude comet on images taken during the Siding Spring Survey with the 0.5-m Uppsala Schmidt on
October 23.49. Following this he was able to locate prediscovery observations from October 22 and then October 11. The comet was at
perihelion at 1.6 AU in early September and has a period of around 11 years.

Brian Marsden notes on MPEC 2009-Y57 [2009 December 29] that further
[astrometric] observations of this comet are desirable.

2009 U5 (Grauer)
Al D Grauer discovered a 19th magnitude comet on survey images taken with the Mt Lemmon 1.5-m reflector on October 23.46.
The preliminary orbit gave perihelion at 0.6 AU in 2010 August, however it proved to be a more distant object.
The comet is at perihelion at 6.1 AU in 2010 June.

Brian Marsden notes on MPEC 2009-Y42 [2009 December 22] that

The "original" and "future" barycentric values of 1/a are +0.000042
and -0.000228 (+/- 0.000039) AU^-1, respectively.

The small "original" value shows that this comet is on its first
visit to the inner solar system.
2009 U6 (230P/LINEAR)
An apparently asteroidal object of 18th magnitude discovered by LINEAR with the 1.0-m reflector on October 27.43 was
found to show a cometary appearance by other astrometrists,
The comet was at perihelion at 1.5 AU in early August and has a period of around 6.3 years.

Following improved astrometry S. Nakano identified observations of the comet among single-night data from NEAT at the two preceding
apparitions in 1997 and 2002, with it being assigned the identifications 1997 A2 and 2002 Q15. Rob Matson independently located
the images corresponding to these observations, together with some additional ones and provided measurements.
The comet's approach to a distance of 0.88 AU from Jupiter in September 2007 means that the orbital period, currently 6.27 years,
was previously 6.48-6.49 years, with the comet's previous two perihelion passages occurring on 2003 Mar. 3 and 1996 Sept. 4.

2009 U10 (SOHO)(IAUC )
This was a non-group comet discovered in C2 images by Bo Zhou on
2009 October 22.
2009 UG89 (Lemmon)
This unusual object was discovered during the Mt Lemmon Survey with the 1.5-m reflector on October 22.10.
20th magnitude at discovery it is in a retrograde orbit and has a period of around 600 years with perihelion
at 4.3 AU on 2010 November [MPEC 2009-U123, 2009 October 27, 3-day orbit]. Aphelion is at 144 AU.
The object passed 0.5 AU from Jupiter in September. It has a Tisserand criterion value of 2.62. It is a likely
candidate for an extinct comet nucleus. [J Shanklin, 2009 October]

In April 2010 further observations confirmed that it did have cometary characteristics and the designation was
accordingly changed. Perihelion was at 3.9 AU in 2010 December.
Gareth Williams notes on MPEC 2010-H68 [2010 April 28]

The orbit indicates an approach to Jupiter within 0.50 AU
in 2009 September 24. Before this approach the heliocentric orbit varied between
elliptical and hyperbolic. With respect to the solar-system barycenter, the
original and future 1/a are +0.00016198 and -0.00143359, respectively.

.
The large original value shows that the comet was previously in an elliptical orbit.
A/2009 UV18 [LINEAR]
This unusual object was discovered by LINEAR with the 1.0-m reflector on October 22.40 and subsequently linked to an
object found in NEAT images and designated 2004 CN97.
19th magnitude at discovery it has a period of 5.7 years and perihelion is at 1.2 AU on 2010 January 18 [MPEC 2009-U127, 2009 October 29].
The object can pass within 0.22 AU of the earth, and 0.5 AU of Jupiter. It has a Tisserand criterion value of 2.85 and is classed
as an Amor asteroid.
2009 W1 (232P/Hill)
Rik Hill discovered an 18th magnitude comet on November 18.51 during the Catalina Sky Survey with the 0.68m Schmidt.
The comet was at perihelion at 3.0 AU in October and has a period of around 9.5 years.

F. Manca, Bosisio Parini (LC), Italy, has suggested that the comet was observed at its previous perihelion passage as
1999 XO188, the observations of which, all by LINEAR, were given on MPS 9249 and 82876. An orbit was published on MPO 50446.
[CBET 2083, 2009 December 17]

2009 W2 (Boattini)
Andrea Boattini discovered a 19th magnitude comet on November 23.48 during the Catalina Sky Survey with the 0.68m Schmidt.
The comet will reach perihelion in 2010 May and has a perihelion distance of 6.9 AU.

Brian Marsden notes on MPEC 2010-B46 [2010 January 27] that

The "original" and "future" barycentric values of 1/a are +0.000427
and +0.000469 (+/- 0.000084) AU^-1, respectively.

The moderate "original" value suggests that this comet has made a previous
visit to the inner solar system.
2009 W8 (SOHO)(IAUC )
This was a non-group comet discovered in C2 images by Tony Scarmato on
2009 November 23.
2009 WJ50 (233P/La Sagra)
WISE satellite images taken on 2010 February 6 showed that an apparently
asteroidal object discovered by the La Sagra Sky Survey on 2009
November 19.88 showed a cometary appearance. Ground based confirming images
taken by Spacewatch on February 13 and the McDonald Observatory on February 15
confirm a small faint coma. The comet has a period of 5.3 years and reached
perihelion at 1.8 AU in March 2010.

The comet was then identified with asteroid 2005 JR71 by Gareth Williams.

2009 WX51 (Catalina)
WISE satellite images taken on 2010 April 2 and 3 showed that an apparently
asteroidal object discovered by the Catalina Sky Survey on 2009
November 22.25 showed a cometary appearance. There have been no ground based
observations since 2009 December 20 and the object is estimated to be around
20th magnitude. The comet has a period of 5.4 years and was at
perihelion at 0.8 AU at the end of January.
2009 X1 (231P/LINEAR-NEAT)
Comet 2003 CP7 (P/LINEAR-NEAT) was recovered by Gary Hug with his 0.56-m reflector at Sandlot Observatory
on December 11.32.
The indicated correction to the prediction on MPC 62880 is Delta(T) = -0.5 day.
2009 Y1 (Catalina)
A 19th magnitude object discovered by the Catalina Sky Survey with the 0.68m Schmidt on December 17.51 and
reported by Rik Hill was found to show cometary features by
other observers. Peter Birtwhistle also contributed initial astrometric observations. The comet
reached perihelion at 2.5 AU in 2011 January and has a very long period
retrograde orbit..

2009 Y2 (P/Kowalski)
Richard Kowalski discovered a 19th magnitude comet on December 20.12 during the Catalina Sky Survey with the 0.68m Schmidt.
The comet will reach perihelion in 2010 March and has a perihelion distance
of 2.3 AU. It has a period of about 17 years.

Brian Marsden notes on MPEC 2010-D88 [2010 February 27] that further
[astrometric] observations of this comet are desirable.

A/2009 YS6 [Mt Lemmon]
This unusual object was discovered during the Mt Lemmon Survey with the 1.5-m reflector on December 17.39.
21st magnitude at discovery it is in a retrograde orbit and has a period of around 90 years with perihelion
at 1.6 AU in 2011 January [MPEC 2010-T46, 2010 October 7, 10-month orbit]. Aphelion is at 9.3 AU.
The object can pass within 0.5 AU of Saturn, 0.6 AU of Jupiter and 0.41 AU from the Earth.
The orbit has a Tisserand criterion value of 1.80. It is a likely
candidate for an extinct comet nucleus.
Ephemerides of current comets are available on the CBAT
ephemeris page and positions of newly discovered comets are on the
NEO confirmation page.
More information on LINEAR. A list of comets
discovered by selected search programs.
The Northumberland refractor
is the telescope that was used in the search for Neptune.
It now has a 0.30-m f20 doublet lens which gives a stellar limiting magnitude of around
15 at the zenith on good nights.
The Thorrowgood refractor was
built in 1864 and has a 0.20-m f14 doublet lens.
Published by Jonathan Shanklin. Jon Shanklin - jds@ast.cam.ac.uk